JEE Main - Periodic trends atomic and ionic radii ionization enthalpy electron gain enthalpy Online Test (MCQ Quiz)

1. Which of the following factors primarily determines the atomic radius of an atom?

A) Number of neutrons B) Number of protons C) Distance of the outermost electron from the nucleus D) Total number of electrons

2. How does atomic radius generally change across a period in the periodic table?

A) Increases from left to right B) Decreases from left to right C) Remains constant D) Increases from right to left

3. What is the primary reason for the decrease in atomic radius across a period?

A) Increase in the number of electron shells B) Decrease in nuclear charge C) Increase in effective nuclear charge D) Increase in electron-electron repulsion

4. How does atomic radius generally change down a group in the periodic table?

A) Decreases down the group B) Increases down the group C) Remains constant D) Increases up the group

5. What is the main reason for the increase in atomic radius down a group?

A) Decrease in nuclear charge B) Addition of new electron shells C) Decrease in effective nuclear charge D) Increase in ionization enthalpy

6. Which element is expected to have the largest atomic radius among Na, Mg, K, and Ca?

A) Na B) Mg C) K D) Ca

7. Which element is expected to have the smallest atomic radius among Li, Be, B, and C?

A) Li B) Be C) B D) C

8. What is the trend in ionic radii down a group?

A) Generally decreases B) Generally increases C) Remains the same D) Fluctuates unpredictably

9. How does the ionic radius of an anion compare to its parent atom?

A) Smaller than the parent atom B) Larger than the parent atom C) Equal to the parent atom D) Cannot be determined

10. How does the ionic radius of a cation compare to its parent atom?

A) Larger than the parent atom B) Smaller than the parent atom C) Equal to the parent atom D) Always zero

11. Which ion is expected to have the largest radius: S²⁻, Cl⁻, K⁺, or Ca²⁺?

A) S²⁻ B) Cl⁻ C) K⁺ D) Ca²⁺

12. Which ion is expected to have the smallest radius: Li⁺, Na⁺, K⁺, or Rb⁺?

A) Li⁺ B) Na⁺ C) K⁺ D) Rb⁺

13. What is isoelectronic species?

A) Atoms with the same number of neutrons B) Atoms with the same number of electrons C) Atoms with the same number of protons D) Atoms with the same chemical properties

14. In an isoelectronic series, how does the ionic radius change with increasing nuclear charge?

A) Increases B) Decreases C) Remains constant D) Becomes zero

15. Consider the isoelectronic series: O²⁻, F⁻, Na⁺, Mg²⁺. Which species has the largest ionic radius?

A) O²⁻ B) F⁻ C) Na⁺ D) Mg²⁺

16. What is ionization enthalpy?

A) Energy required to remove an electron from a neutral gaseous atom B) Energy released when an electron is added to a neutral gaseous atom C) Energy required to excite an electron to a higher energy level D) Energy released when a gaseous ion gains an electron

17. Which symbol represents the first ionization enthalpy?

A) IE₁ B) IE₂ C) EA₁ D) EA₂

18. How does the first ionization enthalpy generally change across a period?

A) Increases from left to right B) Decreases from left to right C) Remains constant D) Increases from right to left

19. What is the primary reason for the increase in ionization enthalpy across a period?

A) Increase in atomic radius B) Decrease in nuclear charge C) Increase in effective nuclear charge D) Decrease in electron shielding

20. How does the first ionization enthalpy generally change down a group?

A) Increases down the group B) Decreases down the group C) Remains constant D) Increases up the group

21. What is the main reason for the decrease in ionization enthalpy down a group?

A) Increase in nuclear charge B) Decrease in atomic radius C) Increase in shielding effect of inner electrons D) Decrease in effective nuclear charge

22. Which element has the highest first ionization enthalpy in the second period?

A) Li B) Be C) B D) Ne

23. Which element has the lowest first ionization enthalpy in the third period?

A) Na B) Mg C) Al D) Si

24. The ionization enthalpy of Boron (atomic number 5) is lower than that of Beryllium (atomic number 4). What is the reason?

A) Boron has a larger atomic radius B) Boron has a filled s-orbital C) The electron removed from Boron is from a 2p orbital which is higher in energy than the 2s orbital of Beryllium D) Beryllium has a greater nuclear charge

25. The second ionization enthalpy (IE₂) is always __________ the first ionization enthalpy (IE₁).

A) less than B) equal to C) greater than D) unrelated to

26. What is electron gain enthalpy?

A) Energy released when an electron is added to a neutral gaseous atom to form an anion B) Energy required to remove an electron from a neutral gaseous atom C) Energy required to add an electron to a neutral gaseous atom D) Energy released when a gaseous ion gains an electron

27. A negative electron gain enthalpy indicates that the atom __________.

A) readily accepts an electron B) readily loses an electron C) is a noble gas D) is a metal

28. How does electron gain enthalpy generally change across a period?

A) Becomes more negative (or less positive) from left to right B) Becomes more positive (or less negative) from left to right C) Remains constant D) Alternates between positive and negative

29. What is the primary reason for the trend in electron gain enthalpy across a period?

A) Decrease in nuclear charge B) Increase in atomic radius C) Increase in effective nuclear charge D) Decrease in shielding effect

30. How does electron gain enthalpy generally change down a group?

A) Becomes more negative down the group B) Becomes less negative (or more positive) down the group C) Remains constant D) Becomes zero

31. Which element has the most negative electron gain enthalpy in the second period?

A) Li B) B C) F D) Ne

32. Which of the following elements has a positive electron gain enthalpy?

A) Chlorine B) Oxygen C) Nitrogen D) Noble gases

33. The electron gain enthalpy of Fluorine is less negative than that of Chlorine. What is the reason?

A) Fluorine has a larger atomic radius B) Fluorine has a smaller atomic radius, leading to interelectronic repulsion in the compact 2p subshell C) Chlorine has a higher nuclear charge D) Fluorine is more electronegative

34. Which of the following sets of elements shows increasing order of atomic radii?

A) Li < Be < B < C B) C < B < Be < Li C) O < F < Cl < S D) Na < Mg < Al < Si

35. Which of the following sets of elements shows decreasing order of first ionization enthalpy?

A) Li > Be > B > C B) F > O > N > C C) Na > Mg > Al > Si D) Ne > F > O > N

36. Which of the following ions is smallest in size: K⁺, Cl⁻, S²⁻, P³⁻?

A) K⁺ B) Cl⁻ C) S²⁻ D) P³⁻

37. The first ionization enthalpies of Group 1 elements (alkali metals) generally decrease in the order:

A) Li > Na > K > Rb > Cs B) Cs > Rb > K > Na > Li C) Na > Li > K > Rb > Cs D) Li < Na < K < Rb < Cs

38. The electron gain enthalpies of Group 17 elements (halogens) generally become less negative in the order:

A) F > Cl > Br > I B) I > Br > Cl > F C) Cl > F > Br > I D) F < Cl < Br < I

39. Which statement about atomic radii is INCORRECT?

A) Atomic radius decreases across a period due to increasing effective nuclear charge. B) Atomic radius increases down a group due to the addition of new electron shells. C) Noble gases have larger atomic radii than halogens in the same period. D) Cations are smaller than their parent atoms.

40. Which statement about ionization enthalpy is CORRECT?

A) Ionization enthalpy increases down a group. B) Noble gases have very low ionization enthalpies. C) The second ionization enthalpy is always smaller than the first. D) Elements with half-filled or fully-filled electronic configurations have exceptionally low ionization enthalpies.

41. Which statement about electron gain enthalpy is INCORRECT?

A) Electron gain enthalpy generally becomes more negative across a period. B) Electron gain enthalpy generally becomes less negative down a group. C) Noble gases have positive electron gain enthalpies. D) Alkaline earth metals have highly negative electron gain enthalpies.

42. Which of the following is an exception to the general trend of ionization enthalpy in Group 13?

A) B < Al < Ga < In B) Al < Ga < In < Tl C) B > Al D) Ga < In

43. The anomaly in the atomic radii trend in the third period is observed between:

A) Na and Mg B) Al and Si C) Ar and Cl D) Mg and Al

44. The electronic configuration of an element is 1s²2s²2p⁶3s²3p³. What is the trend of its ionization enthalpy compared to the element with configuration 1s²2s²2p⁶3s¹?

A) Higher than the element with 3s¹ B) Lower than the element with 3s¹ C) Same as the element with 3s¹ D) Cannot be compared

45. Which factor has the least effect on the ionization enthalpy of an element?

A) Nuclear charge B) Shielding effect C) Penetration of electrons D) Number of neutrons

46. Consider the elements X, Y, and Z with atomic numbers 11, 12, and 13 respectively. The correct order of their atomic radii is:

A) X > Y > Z B) Z > Y > X C) X > Z > Y D) Y > X > Z

47. Which of the following has the highest electron affinity (most negative electron gain enthalpy)?

A) S B) Se C) Te D) Po

48. The electron gain enthalpy of Nitrogen is positive. This is because:

A) Nitrogen has a very stable half-filled p-subshell B) Nitrogen has a high nuclear charge C) Nitrogen is a non-metal D) Nitrogen has a small atomic radius

49. Which of the following species is diamagnetic?

A) O₂⁺ B) O₂⁻ C) O₂²⁻ D) O₂

50. The ionization enthalpy of Argon is significantly higher than that of Chlorine. This is due to:

A) Argon having a stable octet configuration B) Argon being a noble gas C) Argon having a larger atomic radius D) Both A and B

Periodic trends atomic and ionic radii ionization enthalpy electron gain enthalpy - Online Test

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